4. _Whether there may not sometimes be so great a disparity of density
between the upper and under parts of the Air, as to make a reflecting
Surface?_
5. _Whether, if so, this will not explicate the _Phænomena_ of the Clouds.
An Experiment to this purpose?_
7. _Whether the Rayes from the top of Mountains are not bended into
Curve-lines by inflection? An Argument for it, taken from an Experiment
made on St. _Paul_’s Steeple._
8. _Whether the distance of the Planets will not be more difficult to be
found? What wayes are most likely to rectifie the distance of the Moon: the
way of fitting _Telescopes_ for such Observations. How to make the
Observations, and how from them to find the true distance of the Moon at
any time. How the distance of the Sun may be found by two Observators. The
way by the Dichotomy of the Moon uncertain. That the distance of the Moon
may be less then it has been hitherto suppos’d. _Kepler_’s Supposition not
so probable: the explication of the _Phænomena_ by another _Hypothesis_._
Observ. 59. Of the fixt Stars.
_Of the multitudes of Stars discoverable by the _Telescope_, and the
variety of their magnitudes: 78. Stars distinguisht in the _Pleiades_: that
there are degrees of bigness even in the Stars accounted of the same
magnitude: the longer the Glasses are, and the bigger apertures they will
indure, the more fit they are for these discoveries: that ’tis probable,
longer Glasses would yet make greater discoveries. 5. Stars discover’d in
the _Galaxie_ of _Orion_’s Sword._
Observ. 60. Of the Moon.
_A description of a Vale in the Moon; what call’d by _Hevelius_ and
_Ricciolus_, and how describ’d by them: with what substances the hills of
the Moon may be cover’d. A description of the pits of the Moon, and a
conjecture at their cause: two Experiments that make it probable, that of
the surface of boyl’d Alabaster dust seeming the most likely to be
resembled by eruptions of vapours out of the body of the Moon: that
Earthquakes seem to be generated much the same way, and their effects seem
very similar. An Argument that there may be such variations in the Moon,
because greater have been observ’d in the Sun: because the substance of the
Moon and Earth seem much alike: and because ’tis probable the Moon has a
gravitating principle: this is argued from several particulars. The reason
why several pits are one within another. The use that may be made of this
Instance of a gravity in the Moon._
* * * * *
[1] _Schem._ 2. _Fig._ 1.
[2] Diop. ch. 10. § 9.
[3] _Schem._ 2. _Fig._ 2.
[4] _Schem._ 1.* _Fig._ 3.
[5] _Schem._ 3. _Fig._ 1.
[6] _Schem._ 3. _Fig._ 2.
[7] _Schem._ 4.
[8] _Schem._ 4. _Fig._ 1.
[9] _Schem._ 6. _Fig._ 3.
[10] _Schem._ 6. _Fig._ 3.
[11] _Schem._ 8. _Fig._ 1.
[12] _Schem._ 8. _Fig._ 2.
[13] _Schem._ 9. _Fig._ 1.
[14] See _Schem._ 11. _Fig._ 2.
[15] _Fig._ 1. _Schem._ 36.
[16] _Fig._ 3.